Process of providing bronze-powder and dust colors with a coat of varnish.



E. OBSBR. PROCESS OF PROVIDING BRONZE POWDER AND DUST COLORS Wl'lH AGOAT OF VARNISH APPLICATION FILED SEPT.Z2.1909.

Patented Nov. 22, 1910.

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lSCELLANEOUS PRODUCTS.

UNITE STATES PATENT FT TQE.

ERNST OESER, OF BERLIN, GERMANY.

PROCESS OF PROVIDING BRONZE-POWDER AND DUST COLORS WITH A COAT OFVARNISH.

To all whom it may concern:

Be it known that I, ERNST Onsnn,1nanufacturer, a subject of the GermanEmperor, and resident of No. 10 Pallasstrasse, of Berlin, Germany, haveinvented certain new and useful Improvements in Processes of Pro vidingBronze- Powder and Dust Colors with a Coat of Varnish, of which thefollowing is a specification.

The so-called bronze-powder-a powder made of any kind of metalhas, as iswell known, the drawback that it is too liable to oxidize in consequenceof the spraying before, as well as after, its application and loses, asa result, its original fire. For this reason the metal-powder is veryoften not put on in the powder-form, but mixed directly, with theagglutinant. But in this ivay a great part of the metallic luster getsThe object of the present invention is to provide the metallppjflgr, aswell as other ust colors, which lose some of their luster or appearanceunder the action of the atmospheric air. with a transparent -lay.er-..ofy apni sh, which does not impair the metallic lus ter of the metal or ofthe color, but is able to resist the action of the atmospheric air andacid vapors, which layer is put on before it is applied or put on themarket.

This process consists in mixing the metal powder, or the respective dustcolor, with a varnish and stirring it, so that the mixture forms athinly liquid pulp, which is then converted into spray in a closed spaceby -means of a spraying-apparatus worked by air under pressure. Theagglutinant of the varnish must be of a kind that it volatilizes orevaporates during the passage of the particles of metal or color fromthe sprayingnozzle to the place where they are deposited, that is to saythe particles of metal or color must be perfectly dry and sink down tothe bottom of the respective space without bakmg together. The vapors orgases formed by the volatilization of the dissolvent can be let off bysuitable means.

The drawing shows a sample form of construction of the apparatusrequired for carryingout the process, in Figures 1 and 2, in alongltudinal and cross-section. Fig. 3 is Patented Nov. 22, 1910.

Serial No. 519,061.

an enlarged longitudinal sectional view of the spray nozzle.

a is the chamber forming the closed space, 6 the spraying-nozzle, c theair-conduit opening into the same, the receptacle for the product to besprayed, which receptacle stands in communication with the nozzle, and ea hood covering, like a bell, the opening f, through which the gas islet oii. The chamber is provided with a funnel shaped bottom for thepurpose of facilitatmg the removal of the metal powder or of thedustcolor after the treatment. The vapors or gases formed by thevolatilization of the dlssolvent draw oli in the direction of the arrows9.

.Practical experiments have shown that the varnish sold under the nameof Zapon varnish is best-suited for carrying out the process. But theremay also be used other rapidly drying varnishes which give OH to theair, during the short space of time elapsing between the exit from thenozzle and the falling down of the solid particles of metal or color,their volatile dissolvents.

The metal or color-powder treated in this way is quite as loose asbefore and each particle of the same is covered with a thmvarnish-membrane, by which it is protected against the outsideinfluences which cause the oxidation. The powder can then be used in themanner already known.

hat I claim as my invention and desire to secure by Letters Patent ofthe United States is:

1. The process of coating bronze powder and dust colors with a coat ofvarnish, which consists in mixing the pulverized material with a rapidlydrying varnish, and then spraying the mixture under pressure in a closedchamber and permitting it to drop to the bottom of the chamber as a drypowder.

2. The process for coating bronze powder or dust colors with varnish,consisting in mixing the pulverized material with a rapidly dryingVarnish and reducing the mixture to the powdered form before the masshardens.

3. The process of coating bronze powder and dust colors with a coat ofvarnish, which consists in mixing the pulverized material with a rapidlydrying varnish in a sprayed state, stirring the mixture until it 'formsa thin pulp and then spraying it under pressure in a closed chamber, andpermitting it to drop to the bottom of the chamber as a dry powder.

4:. A dry powdered bronze, the particles o f Which are coated with alayer of transparent varnish.

The foregoing specification signed at Berlin this 10th day of September,1909.

ERNST OESER. In presence of VOLDEMAR HAUPT, HENRY HAsrER.

